Zarro was an associate of the Bajoran criminal Ibudan.

According to a personal calendar file, Ibudan had a meeting with Zarro on a Bajoran transport about a project analysis on stardate 46384. This file, along with others, was reviewed by Odo when he was conducting an investigation into the murder of Ibudan. (DS9: "A Man Alone")

This character was only mentioned in writing.